samba - Aug 2003 - smbumount: "You are not allowed to umount"

Does anybody know why I can smbmount a dir but I cann't smbumount it
inmediately?

It says: "You are not allowed to umount it"

I own the mount point and smbumount is suid root.

Also, I can su root and umount it without any problem,

dist -> Debian testing with samba-3.0.0prebeta2

Thanks in advance.
-- 
Andr?s G?mez Garc?a
Ingeniero en Inform?tica
Telf:  +34 981 91 39 91
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